The present invention relates to an apparatus for making bread at home by manually setting necessary ingredients such as wheat flour, water, yeast, and other materials and automatically kneading, fermenting, releasing gas from, and baking a dough, so that a loaf of bread as it is just baked can be produced at home.
Generally known methods of making breads include the straight dough method, the sponge-dough method, and the soaker process. According to the straight dough method, all the necessary ingredients for making bread, i.e., wheat flour, sugar, salt, skimmed milk, butter, yeast, and water are mixed together into a dough, which is then kneaded, fermented, allowed to release gas, and finally baked. Since the straight dough method is simplest, it is most widely relied upon for making bread in kitchens. The sponge-dough method comprises the steps of mixing part of the dough ingredients, i.e., a substantial portion of wheat flour, yeast, and water, into a sponge, which is then allowed to ferment preliminarily, and then mixing the sponge and the remaining ingredients into a dough, which is fermented and baked. According to the soaker process, all the ingredients but yeast are mixed together, and, after a certain period of time, compressed yeast or dry yeast which has been preliminarily fermented in lukewarm water with a small amount of sugar is also added. The dough is then fermented, allowed to release gas, and finally baked.
Efforts have been made to produce automatic bread making machines for home use. However, various problems have been encountered in designing such automatic bread making machines.
More specifically, since all of the bread ingredients are put into a container and mixed together at the outset in the straight dough method, the yeast absorbs the water and gets activated. If the dough were left as it is for a long period of time, it would be excessively fermented, and the produced bread would be of reduced quality.
Problems of the sponge-dough method are as follows: A space is required for storing the remaining ingredients to be added later. A substantial portion of wheat flour, yeast, and water are first mixed, kneaded, and fermented preliminarily, as described above. Therefore, if the time for baking up the dough were delayed, the dough would be allowed to ferment over a prolonged period of time and hence would be overly fermented. As a result, this method fails to bake bread of good quality at a desired time.
The soaker process is disadvantageous for the following reasons: Since compressed yeast is less available than other yeasts, it is customary to use dry yeast. The dry yeast needs to be subjected to preliminary fermentation with lukewarm water containing a small amount of sugar. Consequently, the dry yeast and the lukewarm water have to be stored separately before the preliminary fermentation. The lukewarm water should be kept at a desired temperature, and attention should be paid to the manner in which the preliminarily fermented dry yeast is charged because it is viscous.
As stated above, the conventional methods of making bread pose various problems in the manufacture and operation of automatic home-use bread making machines.
One conventional automatic bread making machine which has been proposed is illustrated in FIG. 9 of the accompanying drawings. In FIG. 9, the bread making machine includes a casing 1, a chassis 2 disposed in the casing 1, a motor 3, a heater 4, and a baking chamber 6 with its outer periphery covered with a thermal insulation 5, the motor 3, the heater 4, and the baking chamber 6 being fixed to the chassis 2. A kneading container 8 having a kneading blade 7 is detachably mounted in the baking chamber 6, the kneading blade 7 being rotated at a reduced speed by the motor 3 through a belt 9 and pulleys 10, 11 which double as a speed reducer. Above the baking chamber 6, there is disposed an openable hinged lid 13 having an inner lid 12. A water supply unit 14 supplies water into the kneading container 8. The bread making machine also has a temperature sensor (not shown) for detecting the temperature of the kneading container 8, a control unit 15 for controlling the motor 3, the heater 4, the water supply unit 14, and the like, and an input unit (not shown) for setting control conditions for the control unit 15. In operation, all dough ingredients other than water are charged into the kneading container 8, and a desired baking time and other data are entered through the input unit. The water supply unit 14 and the motor 3 starts operating at a prescribed time, and the mixed ingredients are kneaded while detecting the temperature of the kneading container 8. When a prescribed temperature or time period has been reached, the motor 3 is de-energized, and the operation enters a fermentation process. The fermentation process progresses while temperature control is effected by the heater 4 dependent on the temperature of the kneading container 8 and gas is released from the dough several times by rotation of the motor 3. Upon elapse of a prescribed period of time, the heater 4 is energized to bake the dough, which is baked up into bread at a desired time.
In the conventional automatic breading making machine, the ingredients are left as they are in the kneading container 8 after the bread making machine is started and until a time is reached for starting an actual bread making process, in order that bread will be baked up at a desired time. No problem arises when a bread making process is started immediately after the ingredients have been set in the kneading container. However, if the dough ingredients are set in the kneading container 8 at night and are to be baked in the next morning, water would start fermenting yeast before the ingredients are kneaded, thus failing to make bread. To avoid this problem, water is separately stored, and will be supplied from the water supply unit 14 at the time the ingredients start being kneaded. Therefore, the water supply unit 14 comprising a large water tank and a pump mechanism is indispensable, with the result that the bread making machine is large in size. Where water is stored for a long period of time, its temperature is increased particularly when it is hot during summer, for example. Therefore, the temperature of the dough will also be high causing the yeast to be too activated to make good bread. When it is cold during winter, stored water is of lowered temperature. If cold water were brought into touch with the yeast at the time of supplying the water, the yeast would be killed, also failing to make good bread. If atmospheric temperature were much lower, stored water would be frozen and no bread could be made at all. In order to prevent water temperature from dropping, it has been prior practice to employ a thermally insulated water tank or cool stored water with ice. Where the ingredients including yeast start to be kneaded while water is being supplied, the dough stimultaneously begins to ferment, and at the same time the temperature of the dough rises due to the kneading process. Therefore, unless the kneading time interval were varied dependent on the temperature of the dough at the time of starting kneading the dough, the temperature of the dough would become too high or low, and no desirable bread would be produced. Conversely, if the kneading time period were controlled so that the dough would be of an optimum temperature, the time period in which to allow the dough to ferment would be varied, thereby causing the dough to excessively or insufficiently be fermented. Therefore, bread could not stably be made. Moreover, the dough may insufficiently or excessively be kneaded dependent on the temperature of the dough at the time of starting to knead the dough. This also fails to make desirable bread.